Thesis
Identification of chromosomal locations associated with the behaviors of tail biting and being a victim of tail biting in the domestic pig
Washington State University
Master of Science (MS), Washington State University
2011
Handle:
https://hdl.handle.net/2376/101311
Abstract
Tail biting is a swine production and animal welfare concern, affecting up to 8.5% of pigs in some countries. Although management and environmental effects have been identified, none have extinguished this behavior. The purpose of this study was to determine if loci were associated with tail biting and being victims of tail biting in a population of Norwegian crossbred Duroc pigs while comparing the effects of four different types of analyses. Pigs were collected as trios, consisting of a tail biter, a victim of tail biting and a control from the same pen from 47 farms. The four methods of genome-wide association analysis compared to determine if there was an association with tail biting or being a victim of tail biting were GRAMMAR-GC, PLINK case-control, GenABEL case-control and GenABEL egscore with and without covariates which varied by how they accounted for the non-independence of meiosis of related animals, population stratification and possibility of confounding through farm management or the gender of the animal. The GRAMMAR-GC analyses identified associations with victims of tail biting on SSC10 (P = 3.9x10-5), but no associations (P < 5x10-5) were identified with tail biting. The PLINK analyses identified associations with tail biting on SSC16 (P = 1.6x10-5) and with a genetic marker unassigned to a chromosome (P = 3.9x10-5). An association with victims of tail biting on SSC18 (P = 7.0x10-6, P = 3.4x10-5), SSC9 (P = 3.9x10-5) and SSC1 (P = 4.7x1-5) were also identified with PLINK. The GenABEL case-control analyses found an association with a SNP unassigned to a chromosome (P = 5x10-5) with tail biting and with tail biting victims on SSC18 (P = 3.9x10-5). The GenABEL eg score analyses, with and without covariates, did not identify any loci associated with either behavior. When sex and farm location were considered as covariates, it did not alter the genetic association in either comparison. The identification of loci associated with tail biting or being a victim of tail biting provides a foundation upon which further studies may be conducted to reduce these behaviors through genetic selection.
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Details
- Title
- Identification of chromosomal locations associated with the behaviors of tail biting and being a victim of tail biting in the domestic pig
- Creators
- Kaitlin Marie Wilson
- Contributors
- Holly L. Neibergs (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Animal Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525396201842
- Language
- English
- Resource Type
- Thesis